For ease of use in GHCi, there is a Show instance, as
demonstrated above.

If the above rendering functions aren’t suited for your purpose, you
can run the monad directly via execHtml and use the more low-level
blaze Builder, which has a plethora of output modes in
Blaze.ByteString.Builder.

See the documentation for the Lucid module for information about
using it as a monad transformer.